Updated: It’s a done deal.

Earlier: Business Insider is reporting that Twitter is buying social TV analytics company Bluefin Labs. We’ve reached out to Bluefin and Twitter for comment. So far, no official confirmation, but it sounds like the deal is close to finalizing.

If this is the case, Twitter is clearly making an even bigger bet to monetize around TV. Earlier this year, Twitter announced a deal with Nielsen — which had just acquired SocialGuide — to create a Twitter TV rating. The idea: to reinforce with TV advertisers that a Twitter media buy amplifies your TV buy.

The approach seems to be paying off: during the Super Bowl, many TV advertisers bought promoted tweets and trends, and 38% of commercials featured a hashtag. It took just four minutes after the lights went out for the first Twitter advertiser to bid on “power outage” as a search term, Twitter said.

Bluefin Labs’ specialty is a deep analysis of social data, especially around TV advertisers. For example, Bluefin tracks the most social brands and TV commercials, which it provides to Lost Remote every week. Together with the Nielsen Twitter TV rating, the acquisition would bolster Twitter’s advertising story and further tie the company to TV media buys.

It also would illustrate that Twitter believes that analytics — once the sole domain of ecosystem partners — has become core to its ability to monetize. We have to wonder if companies that help distribute Twitter for TV, like Mass Relevance, are next on the shopping list.

Bluefin Labs has raised $20.5 million to date, which means the price tag would likely make it the biggest social TV acquisition we’ve seen so far. More coming…